Datasets.
Following the previous works, we evaluate our approach on datasets CUB [1]}
and COCO [2]}.
The CUB dataset contains 200 bird species with 11,788 images, where 150 species with 8,855 images are used as the training data, and the remaining 50 species with 2,933 images as the test data. Each image has 10 related captions in the CUB dataset. The COCO dataset has 80k images for training and 40k images for evaluation. Each image has 5 related captions in the COCO dataset.
